The most recent numbers as of September 2013 are in. With over 36% of users on Jelly Bean and 21% on Ice Cream Sandwich, you can see the move of the market over the past year. Most people are getting rid of their older devices and moving over to newer and more upgradeable devices. There is some new features in these newer versions, but the main thing you need to focus on it device hardware and your app performance. With the majority of the market in newer more powerful devices, we can push apps to do more and demand more from devices which still providing a very good user experience.